Method of constructing a suspended floor

ABSTRACT

A method of constructing a suspended floor is described in which a plurality of beam-forming formwork assemblies are located in substantially parallel alignment, the beam-forming formwork assemblies are supported in support assemblies on a support base in stable equilibrium, a plurality of floor-forming formwork assemblies are located between the beam-forming formwork assemblies for support thereon, concrete is poured in said formwork assemblies, the concrete is allowed to set, and the formwork assemblies are removed from the set concrete for re-use.

TECHNICAL FIELD

This invention relates to a construction system and in particular tofloor-forming formwork and to flooring systems and methods. However itwill be understood that the invention is also applicable to wallingformwork and to walling systems and methods.

The invention has particular but not exclusive application to flooring,to formwork therefor, and to formworking methods and systems for theconstruction of suspended concrete slab floors in housing, on slopes orin multilevel buildings.

BACKGROUND OF INVENTION

Construction methods are known in which prestressed concrete beams areplaced at regular intervals along the supports for a suspended slab. Thebeams have edges which support planar sheets located therebetween andwhich constitute the formwork for the slab. Unless the support sheetshave considerable thickness and/or strength, the beams are locatedrelatively close to each other to prevent sagging of the support sheetswhen the concrete is poured and to withstand construction point loadingswithout failure. Centres of more than 600 mm are not recommended. Anexample of such a known flooring system is illustrated for comparativepurposes in FIGS. 1 and 3.

It is also known in the preparation of concrete floors to locate archedformwork between supports. Australian patents 111529, 147246 and 168002and my Australian petty patent 653697 illustrate known systems. Myearlier system is also illustrated for comparative purposes in FIGS. 2,4 and 5.

It is known to cast elongate reinforced concrete members in moulds or ina continuous or pseudo-continuous fashion. In one method, thereinforcement means is laid out and thereafter a concrete extruder ispassed along the length of the reinforcement means to effectively "coat"the reinforcement means and form the elongate reinforced concretemember.

Integral slab and beam construction systems are also known. U.S. Pat.No. 4,685,264 illustrates one such system.

SUMMARY OF INVENTION

The present invention aims to provide an alternative to knownconstruction systems and methods.

This invention in one aspect resides broadly in a method of constructinga suspended floor, the method including:

positioning a plurality of support assemblies on a support base, and

suspending a beam-forming formwork assembly from each said supportassembly, each said support assembly supporting the beam-formingformwork assembly suspended therefrom in stable equilibrium.

As used herein the expressions "suspend", "suspending" and "suspended",in relation to the beam-forming formwork assemblies, indicate that thebeam-forming formwork assemblies hang from a support assembly.

The beam-forming formwork assemblies can be arranged in any suitableconfiguration. They could for example radiate outwardly from a hub, orthey could be inclined at an angle. However it is preferred that theplurality of beam-forming formwork assemblies are located insubstantially parallel alignment.

In a preferred embodiment the support assemblies are substantiallycradle-like and have arms converging from a base to define an open neckadapted to receive a beam-forming formwork assembly therethrough forsuspended support therefrom.

As used herein the expression "cradle-like" is meant to include supportswhich are adapted to cradle the beam-forming formwork assemblies andincludes supports which are substantially U-shaped in cross-section andincludes yoke-like and stirrup-like supports.

The method may also include locating a plurality of floor-formingformwork assemblies between the beam-forming formwork assemblies forsupport thereon.

The method may further include:

pouring concrete in the floor-forming and beam-forming formworkassemblies;

allowing the concrete to set, and

removing the formwork assemblies from the set concrete for re-use.

Suitably the beam-forming formwork assemblies include a plurality ofbeam-forming formwork modules having a channel member constituting amould for forming a beam, first support means associated with eachflange of the channel member for engagement by the support assembliessuch that the channel member is suspended therefrom in stableequilibrium, and second support means associated with each flange of thechannel member for supporting floor-forming formwork assembliestransversely thereof.

In a preferred embodiment the floor-forming formwork assemblies includea plurality of floor-forming formwork modules adapted to withstand aconstruction point loading without failure. The floor-forming formworkmodules may be fixedly mounted in mounting means adapted to be supportedon the second support means. It is preferred that the floor-formingformwork modules are arched.

In another aspect this invention resides broadly in a support assemblyfor supporting a beam-forming formwork module having a channel memberconstituting a mould for forming a beam and support means associatedwith each flange of the channel member, the support assembly including:

a substantially cradle-like member having arms converging from a base todefine an open neck adapted to receive a beam-forming formwork moduletherethrough such that the channel member is suspended from the supportassembly by the support means and supported thereby in stableequilibrium.

It is preferred that the base is arched.

In another aspect this invention resides broadly in a formwork systemfor a suspended floor, the system including:

a plurality of beam-forming formwork modules each having a channelmember constituting a mould for forming a beam, first support meansassociated with each flange of the channel member such that the channelmember is supportable on a support assembly in stable equilibrium, andsecond support means associated with each flange of the channel memberfor supporting floor-forming formwork assemblies transversely thereof;

a plurality of support assemblies for supporting the beam-formingformwork modules, the support assemblies being substantially cradle-likeand having arms converging from a base to define an open neck adapted toreceive a beam-forming formwork module therethrough such that thechannel member is suspended from the support assembly by the firstsupport means and supported thereby in stable equilibrium, and

a plurality of arched floor-forming formwork modules extendable betweenbeam-forming formwork modules and supportable on the second supportmeans thereof.

In another aspect this invention resides broadly in a method ofconstructing a suspended floor, the method including:

positioning a plurality of support assemblies on a support base;

suspending a plurality of beam-forming formwork assemblies of givencross-section from the support assemblies, the beam-forming formworkassemblies being supported thereby in stable equilibrium, and

suspending a beam-forming insert in a beam-forming formwork assemblywhereby a beam of lesser cross-section than the given cross-section canbe formed.

It is preferred that the plurality of beam-forming formwork assembliesare located in substantially parallel alignment. The beam-formingformwork assemblies preferably include a plurality of beam-formingformwork modules having a channel member of given cross-sectionconstituting a mould for forming a beam, first support means associatedwith each flange of the channel member such that the channel member issupportable on a support assembly in stable equilibrium, and thebeam-forming insert preferably includes a channel member constituting amould of lesser cross-section for forming a beam and flange means forsupporting the channel member on the first support means.

In another aspect this invention resides broadly in a formwork systemfor a suspended floor, the system including:

a plurality of beam-forming formwork modules each having a channelmember of given cross-section constituting a mould for forming a beam,first support means associated with each flange of the channel membersuch that the channel member is supportable on a support assembly instable equilibrium, and second support means associated with each flangeof the channel member for supporting flooring formwork assembliestransversely thereof;

a plurality of beam-forming inserts each having a channel member oflesser cross-section constituting a mould for forming a beam and flangemeans for supporting an insert on the first support means;

a plurality of support assemblies for supporting the beam-formingformwork modules, the support assemblies being substantially cradle-likeand having arms converging from a base to define an open neck adapted toreceive a beam-forming formwork module therethrough such that thechannel member is suspended from the support assembly by the firstsupport means and supported thereby in stable equilibrium, and

a plurality of arched flooring formwork modules extendable betweenbeam-forming formwork modules and supportable on the second supportmeans thereof.

In another aspect this invention resides broadly in a flooring systemfor a suspended floor, the flooring system including:

a plurality of support beams having support means for supportingformwork modules, and

at least one arched formwork assembly having a plurality of archedformwork modules adapted to withstand a construction point loadingwithout failure, the modules being fixedly mounted in mounting meansadapted to be supported on the support means.

The support means may comprise a step or reglet in the support beam oralternatively the support means may include a spigot located in anaperture in the support beam.

In another aspect this invention resides broadly in a method ofconstruction including:

preparing a support base for supporting a construction;

supporting a plurality of support members on the support base, thesupport members having support means for supporting a formwork assembly;

locating at least one arched formwork assembly between the supportmembers to constitute formwork for the construction, the arched formworkassembly having a plurality of arched formwork modules fixedly mountedin mounting means adapted to be supported on the support means, and

placing concrete in the formwork to form the construction.

In one preferred embodiment the construction is a suspended floor and inanother embodiment the construction is a wall.

In another aspect this invention resides broadly in a method ofconstructing a suspended floor, the method including:

preparing a support base for supporting the suspended floor;

locating a plurality of support beams on the support base, the supportbeams having support means for supporting a formwork assembly;

locating at least one arched formwork assembly between the beams toconstitute formwork for the suspended floor, the arched formworkassembly having a plurality of arched formwork modules adapted towithstand a construction point loading without failure, the modulesbeing fixedly mounted in mounting means adapted to be supported on thesupport means, and

placing concrete in the formwork to form a suspended slab floor.

In another aspect this invention resides broadly in a method ofconstructing a suspended floor, the method including:

preparing a support base for supporting the suspended floor;

locating a plurality of beam-forming formwork assemblies on the supportbase, the beam-forming formwork assemblies having support means forsupporting floor-forming formwork modules;

locating a plurality of arched floor-forming formwork modules on andbetween the beam-forming formwork assemblies to constitute formwork forthe suspended floor, the floor-forming formwork modules being adapted towithstand a construction point loading without failure, and

placing concrete in the formwork to form the construction;

the arrangement being such that the beam-forming formwork assembliesand/or the floor-forming formwork assemblies can be re-used.

In another aspect this invention resides broadly in a method ofconstructing a suspended floor, the method including:

preparing a support base for supporting the suspended floor;

locating a plurality of beam-forming formwork assemblies on the supportbase, the beam-forming formwork assemblies having support means forsupporting a floor-forming formwork assembly;

locating a plurality of arched floor-forming formwork assemblies on andbetween the beam-forming formwork assemblies to constitute formwork forthe suspended floor, the arched floor-forming formwork assemblies havinga plurality of arched floor-forming formwork modules adapted towithstand a construction point loading without failure, the modulesbeing fixedly mounted in mounting means adapted to be supported on thesupport means, and

placing concrete in the formwork to form the construction;

the arrangement being such that the beam-forming formwork assembliesand/or the floor-forming formwork assemblies can be re-used.

In another aspect this invention resides broadly in a method ofconstruction including:

aligning a plurality of rib-forming formwork assemblies having aplurality of rib-forming formwork modules, the modules having a channelmember constituting a mould for forming a rib and support meansassociated with each flange of the channel member for supportingpanel-forming formwork assemblies transversely thereof to form onesurface of a panel;

locating a plurality of panel-forming formwork assemblies between therib-forming formwork assemblies for support thereby;

pouring concrete in the panel- and rib-forming formwork assemblies;

allowing the concrete to set, and

removing the formwork assemblies from the set concrete for re-use.

The panel may comprise a floor, wall or any other type of panel.

The formwork assemblies may be located adjacent an embankment to form aretaining wall. Alternatively other panel-forming formwork assembliesmay be located opposite the plurality of rib- and panel-forming formworkassemblies to form the other surface of the panel.

The other panel-forming formwork assemblies may be planar formwork.Alternatively other rib-forming formwork assemblies can be locatedopposite the plurality of rib-forming formwork assemblies to form ribson the other surface of the panel.

The opposed rib-forming formwork assemblies may be located directlyopposite each other. Alternatively, the other rib-forming formworkassemblies can be offset relative to the plurality of rib-formingformwork assemblies.

The opposed formwork assemblies may be independently or separatelysupported before and during the pouring of concrete. However it ispreferred that the pluralities of rib-forming and panel-forming formworkassemblies are braced relative to the other rib-forming andpanel-forming formwork assemblies before the concrete is poured.

DESCRIPTION OF DRAWINGS

In order that this invention may be more easily understood and put intopractical effect, reference will now be made to the accompanyingdrawings which illustrate a preferred embodiment of the invention,wherein:

FIGS. 1 to 5 illustrate known construction systems;

FIG. 6 is a perspective view of a formwork assembly used in the system;

FIGS. 7A and 7B are end and plan views respectively of the formworkassembly illustrated in FIG. 6;

FIGS. 8 to 10 illustrate a construction system in accordance with theinvention wherein un-stressed beams are poured in-situ with the archedform work therebetween;

FIG. 11 illustrates beam-forming formwork for an integral reinforcingbeam in the construction system;

FIGS. 12 and 14 illustrate formwork supports for supporting the formworkof FIG. 11;

FIG. 13 is a cross-sectional view of the formwork support of FIG. 12supporting the formwork of FIG. 11;

FIGS. 15 and 16 illustrate optional features for the formwork support;

FIG. 17 is a side elevation of the construction system showing theformwork in place before the floor is poured;

FIGS. 18 and 19 are sectional elevations of the system as illustrated inFIG. 17 along sections BB and AA respectively;

FIG. 20 is a perspective view of a beam-forming insert;

FIGS. 21 and 22 illustrate beam-forming inserts of lesser cross-sectionsuspended in the beam-forming channel;

FIGS. 23A and 23B are sectional elevations of a retaining wallconstructed in accordance with the invention;

FIGS. 24A and 24B, 25A and 25B, and 26A and 26B are sectional elevationsillustrating alternative walls constructed in accordance with theinvention (FIGS A and B showing the formwork before and after pouringrespectively);

FIG. 27 illustrates boxing formwork for use when a transverse supportbeam is integrally cast with a suspended slab, and

FIG. 28 is a cross-sectional view showing the formwork in place beforepouring a suspended slab having an integrally cast transverse supportbeam.

DESCRIPTION OF PREFERRED EMBODIMENT OF THE INVENTION

As illustrated in FIGS. 2 and 4, in my earlier suspended slab flooringsystem prestressed beams 110 are spaced apart and located on supportingbrick work 112. Arched flooring supports 114 are seated on beam ledges116 in an overlapped array so that the space between adjacent beams isfilled. The arched floor supports may include strengthening ribs 118formed in the sheet material in a circumferential direction. As can beseen in FIG. 5, the arched flooring supports can be lengths ofcorrugated material having a curvature in the direction of thecorrugations.

Alternatively as seen in FIGS. 6, 7A and 7B, an arched formwork assembly128 according to the invention can be utilized. Formwork assembly 128has a number of arched formwork modules 114A located on a pair of siderails 130,132 in the form of angles although other rails such as flatsor channels can be used. The formwork modules 114A are positioned onrails 130,132 in overlapping array to provide overlapping segments 136and fixed to rails 132 by spot welds 138. Rails 130,132 do not extend tothe ends of the outer modules 114. Because rails 130,132 stop short ofthe ends, end edges 140 can overlap and nest with corresponding endedges on adjoining formwork assemblies.

The formwork assembly illustrated has three lengths of arched corrugatedmaterial, each 900 mm in length with a nominal span of 1200 mm. Theformwork assembly is approximately 2700 mm long and spans 1200 mm.

The arched supports may be made from aluminium, zinc alumina, fibrocement, concrete, galvanised iron or steel, plastics or other suitablematerial.

In use, prestressed beams are located as described above with regard tothe prior art, and arched formwork assemblies 128 and/or formworkmodules 114A are placed between adjacent beams in overlapping array.Concrete is then poured to a depth above the top of the beams.

As can be seen in FIGS. 8 to 10 a construction system in accordance withthe invention need not utilize pre-stressed beams and beams may bepoured in-situ with formwork therebetween. It will be appreciated thatwhilst arched formwork modules are described and illustrated, in thisaspect of the invention the floor-forming formwork modules spacedbetween the integrally formed beams need not be arched.

Channel shaped formwork 50 includes a beam-forming channel 10 for thebeams is linked to an channel shaped formwork by link arms 51 havingnotches 52 for receiving the edges of arched formwork modules orassemblies 54. Link arms 51 are spot welded to channel shaped formwork50 along the length thereof. The channel assemblies are placed inside-by-side array on support wall 53 as seen in FIG. 9. Reinforcingsteel 55 is placed in the channels, arched support assemblies or modules54 placed therebetween and concrete 56 poured as seen in FIG. 10. Thechannel shaped formwork 50 overlap at junction 59 and at this junctionthe assembly is supported by a vertical support post 58 as seen in FIG.9. Other supporting arrangements are possible such as running a barthrough lugs located on the base of beam forming channel 10.

As can be seen in greater detail in FIG. 11; the channel shaped formwork50 shown inverted, beam includes forming channels 10 formed by base 12and inclined sidewalls 13 and 14. Side channels 15 and 36 are formed atthe outer edge of sidewalls 13,14. Channels 15 and 36 are formedrespectively by bases 16,17 and side walls 13,14 and 18,19. Anglesections 20, 23 extend outwardly from the outer edge of side walls 18,19and are formed respectively by legs 22,21,25 and 24.

If beam forming channels 10 are directly supported on their base 12during preparation of the slab formwork in the manner illustrated inFIG. 9, the formwork assembly may tend to become unstable. In accordancewith the present invention the formwork assembly can be supported instable equilibrium by supporting beam channels 10 along portions oftheir side channels 15, 36 in stirrup-, cradle- or yoke-like supports.

As can be seen in FIGS. 12 and 14 stirrup supports 26,37 have a pair ofside arms 30,31 converging from an arched base 27 to an open neck.Arched base 27 meets sidearms 30,31 at corners 28,29. The upper ends ofside arms 30,31 are curled over as in FIG. 14 to form support channels34,35 or alternatively as seen in FIG. 12, support arms 33,32 in theform of lengths of box tubing are welded thereto. The depth of thestirrup support is greater than the depth of the beam channel.

FIG. 13 illustrates a beam forming channel 10 supported in stirrupsupport 26 by engagement of arms 33,32 in side channels 15,36. It canalso be seen in this illustration how arched formwork modules 54 areseated in steps in the channel shaped formwork modules 50 formed bysidewalls 18,19 and legs 22,25.

When corners 28,29 of stirrup support 26 are positioned on a supportingmember (for example a timber beam 60 as seen in FIGS. 17 and 18), it canbe seen in FIG. 13 that beam forming channel 10 is supported in stirrupsupport 26 in stable equilibrium in that the points of support of archedformwork modules 54 with stirrup support 26 on legs 22,25 are inwardlydisposed relative to corners 28 and 29. Furthermore, when load isapplied to the arched modules 54 under the load of concrete beingpoured, a degree of resilience in the arched module permits the moduleto flex downwardly under load thereby shifting the points of contactfurther inwardly of corners 28 and 29 and tending to close the gapbetween the edge of modules 54 and sidewalls 18 and 19. The gap islargely self-sealed and should the gap remain it will seal with concreteduring the pour.

In use, particularly during slab formwork preparation when workers willbe walking across arched formwork modules 54, it can be seen thatdownward force is applied inwardly of support corners 28,29 andconsequently there is no tendency for stirrup support 26 to rotate aboutsupport corners 28,29. Moreover the suspended support of beam-formingchannels 10 in stirrup supports 26 supports the slab in stableequilibrium during the pour and prior to stripping the formwork from thecured slab for re-use.

Stirrup support 26 are resilient and arms 30,31 can flex about archedbase 27 which can also flex under load. Consequently during the pour,the downward force from the weight of concrete in beam channels 11 asthe pour commences results in the support arms of the stirrup supportbeing firmly engaged in the upper channels of the beam channels therebyenhancing the stability of the formwork system.

As can be seen in FIGS. 15 and 16, stirrup supports 26 can include apair of opposed members 80,81 adapted to restrain beam-forming channels10 against lateral movement, and a pair of ears 82,83 having aperturestherein for nailing the support stirrup to a timber beam on which it issupported. Other ears (not shown) can be affixed perpendicular to thoseillustrated whereby the stirrup supports can be nailed to the edge ofthe timber beam. The base 12 of beam-forming channel 10 can haveapertures through which a screw 84 can be located for supporting timberbattens or the like once the floor has been cast. Screw 84 is fixed towire tie 85 for retaining the screw within the cast beam.

In use as seen in FIGS. 17 to 19, beam-forming channels 10 overlap atjunction 59 and are supported on stirrups 26 by timber beam 60 which isin turn supported by a vertical support post 58 and pad 61. The outerends of beam-forming channels 10 abut the inner face of brick supportingwall 53. FIG. 19 illustrates recesses 63 which are made in the wall forforming an extension of the beam onto the supporting wall, and alsoillustrates grouting 62 which is packed on the wall to support thearched formwork modules 54.

As can be seen in FIGS. 27 and 28, a transverse support beam can be castintegrally with the suspended floor. Formwork battens 105 are located atopposite sides of support plate 108 which is supported on beam 60 asdescribed above. Battens 105 have cutouts 106 for receiving andsupporting the ends of beam-forming channels 10, and arches 107 forsupporting the arched formwork modules 54 which for the sake of clarityhave not been illustrated in FIGS. 17 and 28.

When the slab has cured the formwork can be stripped for re-use.Vertical supports 58 are removed together with timber beams 60 enablingstirrup supports 26 to be released. The channel shaped formwork modules50 are then stripped from the beams allowing the arched formwork modules54 to be stripped from the slab. Similarly if a transverse support beamhas been formed, removal of vertical support 58 and beam 60 allowssupport plate 108 to be removed. Battens 105 are then removed downwardlyaway from the floor beams.

So that smaller dimension beams may be formed simply by placingappropriate formwork channels in the standard formwork assemblies whenconstructed, a beam-forming insert 71 is provided and as seen in FIG.20, consists of a channel having sides 73 and 74 and base 72. A pair offlanges 75 and 76 extend outwardly of the upper edges of sides 73 and 74and are adapted to sit on the upper supports of beam-forming channel 10by means of which beam-forming channel 10 is suspended in supportassembly 26 (as seen in FIG. 13).

FIGS. 21 and 22 illustrate differing sized beam-forming insertspositioned in beam-forming channel 10. The inserts illustrated haveuniform depth however it will be appreciated that the inserts can havevariable depth along the length of the insert to facilitate theconstruction of a beam of variable depth.

If it is desired that a ceiling be affixed to the underside of thefloor, as for example in a multi-level building, timber battens can belocated in the bottom or against the sides of beam-forming channel 10before the pour. The battens are thus exposed after the formwork isstripped and a ceiling can more easily be nailed to the timber battensthan gun-nailed to the concrete beam.

It will be appreciated that beam-forming channel 10 may be used as arib-forming channel together with formwork modules 54 in theconstruction of walls.

As can be seen in FIGS. 23A and 23B, rib-forming channels 10A are spacedrelative to embankment 89 by stays 90 and formwork modules 54 mountedagainst the support flanges of rib-forming channel 10A as describedabove and spaced from embankment 89 by struts 91. Stays 90 arereleasably capped by caps 100 and when the concrete is set afterpouring, rib-forming channels 10 are stripped by removing releasablecaps 100 and then formwork modules 54 are stripped for re-use.

Alternatively as seen in FIGS. 24A and 24B, a wall ribbed on one sideand planar on the other can be constructed by spacing rib-formingchannels 10A relative to planar formwork 101 by means of stays 92 withformwork modules 54 being mounted against the support flanges of thechannels by struts 93.

In another embodiment seen in FIGS. 25A and 25B, a double ribbed wall isconstructed by spacing rib-forming channels 10A relative to otherrib-forming channels 94 by means of stays 96 and spacing formworkmodules 54 relative to other formwork modules 95 by struts 97.

Alternatively as seen in FIGS. 26A and 26B, a thinner wall of equalstrength or a greater surface area for the same volume of concrete canbe constructed if the rib-forming channels are off-set. A double ribbedwall with off-set ribs is constructed by spacing rib-forming channels10A off-set relative to other rib-forming channels 98 by means of stays88 which connect the base of a rib-forming channel 98 to a bridge member86 spanning between the bases of adjoining and opposite rib-formingchannels 10A. Formwork modules 54 are spaced relative to other formworkmodules 99 by struts 87 between the base of a rib-forming channel and anopposed formwork module.

In the embodiments of FIGS. 24, 25 and 26, the rib-forming channels andthe panel-forming formwork modules are stripped for re-use by uncappingthe releasably capped stay, stripping the channel and then stripping theformwork module.

It will be appreciated that the formwork, flooring system andconstruction method in accordance with the invention has a number ofsignificant advantages over known systems. The formwork is of lightergauge than planar formwork for a given strength and so is lighter andcheaper. This also enables the formwork to overlap and minimises slumpdrainage during the pour. The ability to overlap also enables addedstrength to be provided by overlapping the material.

The use of a formwork assembly having a plurality of individual smallerarched support modules saves time during construction leading to quickerconstruction methods at reduced labour costs. Moreover, the smallerlengths used in the formwork assembly described above have the potentialto be more easily and cheaply manufactured by methods other than rollforming, such as pressing or stamping for example.

Because greater separation of beams is possible, fewer beams arerequired leading to further cost savings. For a given floor strength,less concrete is used therefore costs are reduced still further becauseof lower concrete costs as well as the potential for smaller foundationsdue to a reduction in dead loadings. The extra space beneath the floorprovided by the archway enables a greater range of services to be rununder the floor.

The ease of overlapping the beam formwork channels minimises wastage incomparison with systems where formwork is cut to length. The capacity tore-use the formwork provides significant cost benefits in comparisonwith systems where the formwork is not salvaged but rather remains inplace. Such arrangements provide a finishing surface if a concretesurface is not required, but limit the surface to the material of theformwork and are expensive in comparison with the method of the presentinvention. The method of supporting the formwork in stable equilibriumcan reduce set up times and improves safety.

In particular, because the beam-former is suspended at its upper edgesin a cradle-like support bracket the base of which is wider than theneck, the downward resultant force due to workers stepping on theformwork or due to the weight of the concrete, is inside the supportbracket and does not generate an unstable turning moment as occurs whenthe beam former is supported on its base as in prior art arrangements.Furthermore the suspended support of the present invention has theeffect of centring the beam.

The invention enables standard beam-forming assemblies to be used whilstallowing the utilization of re-usable inserts to save on concrete costswhere smaller beams can be used.

It will of course be realized that whilst the above has been given byway of an illustrative example of this invention, all such and othermodifications and variations hereto, as would be apparent to personsskilled in the art, are deemed to fall within the broad scope and ambitof this invention as is herein claimed.

I claim:
 1. A method of constructing a suspended floor, said methodincluding:positioning a plurality of support assemblies on a supportbase, and suspending a beam-forming formwork assembly from each saidsupport assembly, each said support assembly supporting the beam-formingformwork assembly suspended therefrom in stable equilibrium.
 2. A methodas claimed in claim 1, wherein said plurality of beam-forming formworkassemblies are located in substantially parallel alignment.
 3. A methodas claimed in claim 1, wherein said support assemblies are substantiallycradle-like and have arms converging from a base to define an open neckadapted to receive a beam-forming formwork assembly therethrough forsuspended support therefrom.
 4. A method as claimed in claim 3, saidmethod including:locating a plurality of floor-forming formworkassemblies between said beam-forming formwork assemblies for supportthereon; pouring concrete in said flooring and beam-forming formworkassemblies; allowing the concrete to set, and removing the formworkassemblies from the set concrete for re-use.
 5. A method as claimed inclaim 3, wherein said beam-forming formwork assemblies include aplurality of beam-forming formwork modules having a channel memberconstituting a mould with side walls for forming a beam, first supportmeans associated with each side wall of the channel member such that thechannel member is supportable on a support assembly in stableequilibrium, and second support means associated with each side wall ofthe channel member for supporting floor-forming formwork assembliestransversely thereof.
 6. A method as claimed in claim 5, wherein saidfloor-forming formwork assemblies include a plurality of floor-formingformwork modules adapted to withstand a construction point loadingwithout failure.
 7. A method as claimed in claim 6, wherein saidfloor-forming formwork modules are fixedly mounted in mounting meansadapted to be supported on said second support means.
 8. A method asclaimed in claim 5, wherein said floor-forming formwork modules arearched.
 9. A support assembly for supporting a beam-forming formworkmodule having a channel member constituting a mould for forming a beamand support means associated with each flange of the channel member,said support assembly including:a substantially cradle-like memberhaving arms converging from a base to define an open neck adapted toreceive a beam-forming formwork module therethrough such that thechannel member is suspended from the support assembly by said supportmeans and supported thereby in stable equilibrium.
 10. A supportassembly as claimed in claim 9, wherein said base is arched.
 11. Aformwork system for a suspended floor, said system including:a pluralityof beam-forming formwork modules each having a channel memberconstituting a mould with side walls for forming a beam, first supportmeans associated with each side wall of the channel member such that thechannel member is supportable on a support assembly in stableequilibrium, and second support means associated with each side wall ofthe channel member for supporting floor-forming formwork assembliestransversely thereof; a plurality of support assemblies for supportingsaid beam-forming formwork modules, the support assemblies beingsubstantially cradle-like and having arms converging from a base todefine an open neck adapted to receive a beam-forming formwork moduletherethrough such that the channel member is suspended from the supportassembly by said first support means and supported thereby in stableequilibrium, and a plurality of arched floor-forming formwork modulesextendable between beam-forming formwork modules and supportable on saidsecond support means thereof.
 12. A method of constructing a suspendedfloor, said method including:positioning a plurality of supportassemblies on a support base; suspending a plurality of beam-formingformwork assemblies of given cross-section from said support assemblies,said beam-forming formwork assemblies being supported thereby in stableequilibrium, and suspending a beam-forming insert of lessercross-section than said given cross-section in a beam-forming formworkassembly whereby a beam is formed when concrete is placed in saidformwork assemblies.
 13. A method as claimed in claim 12, wherein:saidbeam-forming formwork assemblies include a plurality of beam-formingformwork modules having a channel member of given cross-sectionconstituting a mould for forming a beam, first support means associatedwith each side wall of the channel member such that the channel memberis supportable on a support assembly in stable equilibrium, and saidbeam-forming insert includes a channel member constituting a mould oflesser cross-section for forming a beam and flange means for supportingsaid channel member on said first support means.
 14. A formwork systemfor a suspended floor, said system including:a plurality of beam-formingformwork modules each having a channel member of given cross-sectionconstituting a mould for forming a beam, first support means associatedwith each flange of the channel member such that the channel member issupportable on a support assembly in stable equilibrium, and secondsupport means associated with each flange of the channel member forsupporting flooring formwork assemblies transversely thereof; aplurality of beam-forming inserts each having a channel member of lessercross-section constituting a mould for forming a beam and flange meansfor supporting an insert on said first support means; a plurality ofsupport assemblies for supporting said beam-forming formwork modules,the support assemblies being substantially cradle-like and having armsconverging from a base to define an open neck adapted to receive abeam-forming formwork module therethrough such that the channel memberis suspended from the support assembly by said first support means andsupported thereby in stable equilibrium, and a plurality of archedflooring formwork modules extendable between beam-forming formworkmodules and supportable on said second support means thereof.
 15. Aflooring system for a suspended floor, the flooring system including:aplurality of support beams having support means for supporting aformwork assembly, and at least one arched formwork assembly having aplurality of arched formwork modules adapted to withstand a constructionpoint loading without failure, the modules being fixedly mounted inmounting means adapted to be supported on the support means.
 16. Amethod of construction including:preparing a support base for supportinga construction; supporting a plurality of support members on the supportbase, the support members having support means for supporting a formworkassembly; locating at least one arched formwork assembly between thesupport members to constitute formwork for the construction, the archedformwork assembly having a plurality of arched formwork modules fixedlymounted in mounting means adapted to be supported on the support means,and placing concrete in the formwork to form the construction.
 17. Amethod of constructing a suspended floor, the method including:preparinga support base for supporting the suspended floor; locating a pluralityof support beams on the support base, the support beams having supportmeans for supporting a formwork assembly; locating at least one archedformwork assembly between the beams to constitute formwork for thesuspended floor, the arched formwork assembly having a plurality ofarched formwork modules adapted to withstand a construction pointloading without failure, the modules being fixedly mounted in mountingmeans adapted to be supported on the support means, and placing concretein the formwork to form a suspended slab floor.
 18. A method ofconstructing a suspended floor, the method including:preparing a supportbase for supporting the suspended floor; locating a plurality ofbeam-forming formwork assemblies on the support base, the beam-formingformwork assemblies having support means for supporting a floor-formingformwork assembly; locating a plurality of arched floor-forming formworkassemblies on and between the beam-forming formwork assemblies toconstitute formwork for the suspended floor, the arched floor-formingformwork assemblies having a plurality of arched floor-forming formworkmodules adapted to withstand a construction point loading withoutfailure, the modules being fixedly mounted in mounting means adapted tobe supported on the support means, and placing concrete in the formworkto form the construction; the arrangement being such that thebeam-forming formwork assemblies and the floor-forming formworkassemblies can be re-used.